Mining the mineral-rich seafloor is a notion that has captured the hearts (and wallets) of  investors for decades.

But recently, progress has stalled as regulatory uncertainty, environmental concerns, and financial issues put some of the bigger projects on ice.

Market darlings, like Canadian company Nautilus Minerals and its high grade Solwara 1 copper-gold project off the PNG coast, have failed to deliver.

Solwara 1 was going to be the world’s first underwater copper-gold mining operation. The deposit, which sits on the seafloor at a depth of about 1.6km, contains copper grades of up to 7 per cent, and gold grades well over 20 grams per tonne.

It was an amazing concept.

Pic: Nautilus Minerals.

Nautilus has since been delisted from the TSX and is nearing bankruptcy, as funding issues and regulatory squabbles take their toll.

But the fledgling seafloor mining industry could have a new public face as the battery metals thematic gathers pace.

In early June, Canadian start-up DeepGreen managed to raise the $US150m it needs for feasibility studies on its deep-sea battery metals project in the Pacific.

Prices for cobalt, copper and nickel are low (ish) right now, but we know that’s only temporary. A staggering amount of of these metals must be sourced sustainably if the electric vehicle industry is going to get within cooee of its long-term production goals.

The UK, for example, will need 200 per cent of today’s global cobalt production if it is to meet its 100 per cent EV target in 2050.

DeepGreen positions itself as an ethical operator which, unlike pioneer Nautilus Minerals, won’t drill, blast or dig the bottom of the ocean.

DeepGreen’s wants to extract cobalt and other battery metals from small, potato-sized nodules covering the seafloor in the so-called Clarion Clipperton Zone (CCZ).

Harvesting potatoes. Pic: DeepGreen.

The project currently has an inferred resource of 909 million tonnes of wet polymetallic nodules grading 1.3 per cent nickel, 29.2 per cent manganese, 1.1 per cent copper and 0.2 per cent cobalt.

DeepGreen will partner with engineering firm Allseas to develop a harvester and riser system to gather nodules and transport them up to a surface vessel, 4km to 6.5km above the seafloor.

DeepGreen chairman Gerard Barron says the project represents a new, disruptive source of battery metals for the green revolution.

“Extracting battery metals like nickel and cobalt from terrestrial mines is facing many challenges, and the environmental, CO2 and social costs are simply too high,” he says.

“Seafloor polymetallic nodules contain more than enough base metals that the world needs to get to a clean energy economy, and they require no blasting, drilling or digging.

“Indeed, our life cycle sustainability analysis shows that, with regards to NMC [nickel-manganese-cobalt] batteries with copper connectors for electric vehicles, ocean nodules generate at least 75 per cent less CO2 when compared to producing these metals from land ores.”

“Together with Allseas, we’ll engineer a deep ocean nodule harvesting system that will have minimal impact to the deep sea environment, enabling us to bring what we call ‘clean metals’ to market in order to power some of the one billion electric vehicles that are forecast to be produced over the coming three decades.”